As a conventional device for displaying an image on a screen or on a wall surface, so-called monitor and projector are used. A mobile type compact in size and easy to carry is proposed as such monitor and projector.
In Patent Literature 1, a display mode of video information having degrees of reproduction permission for a plurality of observers is determined based on input personal information for each of the observers and viewing restriction information added to digital video contents. The video information is decoded by a decoder according to the display mode, and the decoded video information is displayed according to the display mode in a mutually independent manner, for each viewpoint of the observers who view the video information from different positions via an image display unit and a local video information output unit. Patent Literature 2 also describes a device that determines whether an output is permitted based on information of contents and information of an operator.